Novel three-dimensional cylindrical negative stiffness energy absorption structure and design method thereof

Abstract

The invention discloses a novel three-dimensional cylindrical negative stiffness energy absorption structure and a design method thereof.The novel three-dimensional cylindrical negative stiffness energy absorption structure comprises an energy absorption structure body, the energy absorption structure body is composed of an inner cylindrical face, an outer cylindrical face and an internal periodic structure, and the internal periodic structure is provided with novel biaxial negative stiffness honeycomb unit structures distributed periodically; and each novel biaxial negative stiffness honeycomb unit structure is provided with an upper bent beam structure and a lower bent beam structure. Compared with a traditional hexagonal honeycomb structure, the novel three-dimensional cylindrical negative-stiffness energy absorption structure has better mechanical properties, the energy absorption effect is remarkably improved, good repeatability is achieved, and compared with a traditional two-dimensional negative-stiffness structure, the application range of the three-dimensional cylindrical negative-stiffness energy absorption structure is expanded; the movement requirements of the structure in some aspects are better met, application and popularization are facilitated, and even an assumption is provided for proposing a three-dimensional spherical shell energy absorption structure.

Description

Technical Field

[0001] The invention relates to the technical field of negative stiffness structure design, and in particular to a novel three-dimensional cylindrical negative stiffness energy absorption structure and a design method thereof. Background Art

[0002] Negative stiffness metamaterials are a branch of mechanical metamaterials. Usually, to increase the deformation of the material, the applied external force must also increase, which we call positive stiffness; when the deformation of the material increases but the applied external force decreases, we call this negative stiffness. Negative stiffness structural materials have broad practical application prospects in protective equipment and shock-absorbing equipment due to their excellent reusability. This feature can not only improve the energy absorption performance of the structure, but also be recycled to reduce the cost of materials, and promote the development of structural materials in a sustainable direction. In the field of aerospace, especially under high-speed impact, negative stiffness metamaterials can play a good role in buffering and absorbing energy, protecting the internal payload from damage.

[0003] At present, most of the negative stiffness structural materials that have been published are honeycomb structural materials and lattice structural materials based on bending axis model and tilting axis model. Compared with lattice structural materials, dome model has better energy absorption effect and can withstand forces in multiple directions. However, the negative stiffness structures proposed so far are mostly two-dimensional structures. Some studies on three-dimensional negative stiffness structures are mostly based on arrays of bending axis model and tilting axis model to form a cubic structure that can withstand lateral compression buffering. However, it is still insufficient for buffering energy absorption performance in more directions or even omnidirectionally. Summary of the invention

[0004] In order to solve the above technical problems, a new three-dimensional cylindrical negative stiffness energy absorption structure and a design method thereof are provided. The technical solution solves the problem raised in the above background technology that the negative stiffness structures currently proposed are mainly two-dimensional structures, and some studies on three-dimensional negative stiffness structures are mostly based on arrays of bending axis models and inclined axis models to form a cubic structure that can withstand lateral compression buffering. However, there is still insufficient problem in terms of buffering energy absorption performance in more directions or even omnidirectionally.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A novel three-dimensional cylindrical negative stiffness energy absorption structure comprises an energy absorption structure body, wherein the energy absorption structure body is composed of inner and outer cylindrical surfaces and an internal periodic structure, wherein the internal periodic structure is provided with a periodically distributed negative stiffness honeycomb unit structure, and each of the negative stiffness honeycomb unit structures is provided with two upper and lower bending beam structures.

[0007] Preferably, the interior of the energy absorbing structure body is composed of three layers of novel biaxial negative stiffness honeycomb unit structures, and each layer of the novel biaxial negative stiffness honeycomb unit structures is composed of 18 negative stiffness honeycomb unit structures.

[0008] Preferably, the curved beam parameterized model is:

[0009]

[0010] F = fl 3 / (Elh)

[0011] Δ=d / h

[0012] Q=h / t

[0013] In the formula, is the average distance from any point on the bending beam to the horizontal line connecting the two ends of the beam, h is the amplitude of the bending beam, x is the position on the horizontal line, l is the horizontal length of the bending beam, f is the external force, E is the elastic modulus of the buckling beam material, I is the moment of inertia of the beam, t is the thickness of the beam, d is the lateral displacement of the bending beam, and the geometric parameter Q determines the direction of the relative stress-relative displacement curve. Changing the Q value adjusts the stiffness of the bending beam.

[0014] Preferably, the cosine period length of the hyperbolic beam in the lower part of the new biaxial negative stiffness honeycomb unit structure located in the outermost layer is 50.8 mm, the cosine amplitude is 5.08 mm, the beam thickness is 1.27 mm, the column thickness is 2.54 mm, and the period length of the beam in the upper part of the new biaxial negative stiffness honeycomb unit structure located in the outermost layer is 45.43 mm.

[0015] Preferably, the cosine period length of the upper semi-hyperbolic beam of the novel biaxial negative stiffness honeycomb unit structure located in the middle position is 38.92 mm, the cosine amplitude is 5.08 mm, the beam thickness is 1.27 mm, and the column thickness is 2.54 mm.

[0016] Preferably, the cosine period length of the hyperbolic beam in the upper part of the new biaxial negative stiffness honeycomb unit structure located in the innermost layer is 32.31 mm, the beam thickness is set to 1.27 mm, and the cosine amplitude is 5.08 mm.

[0017] Preferably, the new biaxial negative stiffness honeycomb unit structure located in the middle position has a thickness of 62.42 mm on the radius of the new three-dimensional cylindrical negative stiffness energy absorbing structure, and the new biaxial negative stiffness honeycomb unit structure located in the innermost layer has a thickness of 81.43 mm in the radius direction of the new three-dimensional cylindrical negative stiffness energy absorbing structure.

[0018] Preferably, the diameter of the novel three-dimensional cylindrical negative stiffness energy absorbing structure is 338.29 mm.

[0019] Preferably, the thickness of the three-layer hyperbolic beam honeycomb unit structure in the radius direction of the new three-dimensional cylindrical negative stiffness energy absorbing structure is 81.43 mm, and the inner diameter of the new three-dimensional cylindrical negative stiffness energy absorbing structure is 175.43 mm.

[0020] A novel design method for a three-dimensional cylindrical negative stiffness energy absorbing structure, comprising:

[0021] S1. The new biaxial negative stiffness honeycomb unit structure is made of polyurethane material and is integrally processed by 3D printing technology;

[0022] S2. When verifying the mechanical properties of the new biaxial negative stiffness honeycomb unit structure, the load-bearing compression performance is verified by the finite element software ABAQUS. The specific process is as follows:

[0023] A unit structure model was created in SolidWorks software, imported into ABAQUS, a rigid plate was created to simulate the ground, material parameters were set, and sections were created for it. Both the unit structure and the ground were solid sections.

[0024] The dynamic implicit analysis step is selected, which has a quasi-static effect and is used to simulate the quasi-static compression process. The surface-to-surface contact is adopted between the lower surface of the unit structure and the upper surface of the rigid ground. The friction coefficient is determined according to the actual situation. The penalty function calculation method is adopted. The general contact is set for the overall structure in the initial analysis step to limit the geometric penetration between the models.

[0025] The upper surface of the unit structure is coupled to the center of the cylinder, and the rotational and translational degrees of freedom of the center are restricted to 0, which is in a completely fixed state. The rigid ground is set as a rigid body, and an upward displacement is applied to it.

[0026] The unit structure uses the element C3D20R to mesh the structure, defines the approximate global size as 0.5, and performs nonlinear effect analysis on it. The rigid ground uses the R3D4 discrete rigid element;

[0027] After determining the compression performance of the unit structure, the number of layers is accumulated on the basis of the unit structure. The simulation process of the two-layer and three-layer negative stiffness unit structure is the same as above.

[0028] Compared with the prior art, the present invention provides a novel three-dimensional cylindrical negative stiffness energy absorption structure and a design method thereof, which has the following beneficial effects:

[0029] Compared with the traditional hexagonal honeycomb structure, the novel three-dimensional cylindrical negative stiffness energy absorbing structure of the present invention has better mechanical properties, significantly improved energy absorption effect, and good repeatability. Compared with the traditional two-dimensional structure, the three-dimensional cylindrical negative stiffness energy absorbing structure has expanded its application range and better meets the movement requirements of the structure in certain aspects, which is conducive to promotion and use, and even provides a concept for the proposal of a three-dimensional spherical shell energy absorbing structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the three-dimensional cylindrical negative stiffness energy absorption structure model of the present invention

[0031] Figure 2 A single unit and size diagram of the three-dimensional cylindrical negative stiffness energy absorption structure of the present invention

[0032] Figure 3 The double-layer and three-layer unit structure diagram of the three-dimensional cylindrical negative stiffness energy absorption structure of the present invention

[0033] Figure 4 The finite element simulation process of the compression deformation of the three-layer structure of the three-dimensional cylindrical negative stiffness energy absorbing structure of the present invention

[0034] Figure 5 The experimental process of compression deformation of the three-layer structure of the three-dimensional cylindrical negative stiffness energy absorption structure of the present invention

[0035] Figure 6 The force-displacement curve of the three-layer unit structure finite element analysis of the novel three-dimensional cylindrical negative stiffness energy absorption structure of the present invention

[0036] Figure 7 The experimental process of compression deformation of the three-layer conventional hexagonal honeycomb structure with medium thickness t of the present invention

[0037] Figure 8 The experimental force-displacement curves of the three-layer biaxial negative stiffness honeycomb structure of the present invention and the three-layer traditional honeycomb structure with the same thickness t, as well as the cyclic test curve of the three-layer negative stiffness honeycomb structure.

[0038] The numbers in the figure are:

[0039] 1. New biaxial negative stiffness honeycomb unit structure. DETAILED DESCRIPTION

[0040] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0041] Example 1

[0042] Please refer to Figure 1As shown, a novel three-dimensional cylindrical negative stiffness energy absorbing structure includes an energy absorbing structure body, which is composed of inner and outer cylindrical surfaces and an internal periodic structure. The internal periodic structure is provided with a periodically distributed novel biaxial negative stiffness honeycomb unit structure 1, and each novel biaxial negative stiffness honeycomb unit structure 1 is provided with two upper and lower bending beam structures.

[0043] The interior of the energy absorbing structure body is composed of three layers of negative stiffness hyperbolic beam honeycomb unit structures, and each layer of negative stiffness hyperbolic beam honeycomb unit structures is composed of 18 new biaxial negative stiffness honeycomb unit structures 1.

[0044] The parametric model of the curved beam is:

[0045]

[0046] F = fl 3 / (Elh)

[0047] Δ=d / h

[0048] Q=h / t

[0049] In the formula, is the average distance from any point on the bending beam to the horizontal line connecting the two ends of the beam, h is the amplitude of the bending beam, x is the position on the horizontal line, l is the horizontal length of the bending beam, f is the external force, E is the elastic modulus of the buckling beam material, I is the moment of inertia of the beam, t is the thickness of the beam, d is the lateral displacement of the bending beam, and the geometric parameter Q determines the direction of the relative stress-relative displacement curve. Changing the Q value adjusts the stiffness of the bending beam.

[0050] The cosine period length of the hyperbolic beam in the lower part of the new biaxial negative stiffness honeycomb unit structure located in the outermost layer is 50.8mm, the cosine amplitude is 5.08mm, the beam thickness is 1.27mm, the column thickness is 2.54mm, and the beam period length of the upper part of the new biaxial negative stiffness honeycomb unit structure located in the outermost layer is 45.43mm.

[0051] The cosine period length of the upper half hyperbolic beam of the new biaxial negative stiffness honeycomb unit structure located in the middle position is 38.92mm, the cosine amplitude is 5.08mm, the beam thickness is 1.27mm, and the column thickness is 2.54mm.

[0052] The cosine period length of the upper part of the hyperbolic beam of the new biaxial negative stiffness honeycomb unit structure located in the innermost layer is 32.31 mm, the beam thickness is set to 1.27 mm, and the cosine amplitude is 5.08 mm.

[0053] The new biaxial negative stiffness honeycomb unit structure located in the middle position has a thickness of 62.42 mm on the radius of the new three-dimensional cylindrical negative stiffness energy absorbing structure, and the new biaxial negative stiffness honeycomb unit structure located in the innermost layer has a thickness of 81.43 mm in the radius direction of the new three-dimensional cylindrical negative stiffness energy absorbing structure.

[0054] The diameter of the new three-dimensional cylindrical negative stiffness energy absorption structure is 338.29 mm.

[0055] The thickness of the three-layer hyperbolic beam honeycomb unit structure in the radial direction of the new three-dimensional cylindrical negative stiffness energy absorbing structure is 81.43 mm, and the inner diameter of the new three-dimensional cylindrical negative stiffness energy absorbing structure is 175.43 mm.

[0056] It will be understood by those skilled in the art that Figure 4 and Figure 5 As shown, the load-bearing compression performance of the new three-dimensional cylindrical negative stiffness energy-absorbing structure was verified by combining experiments with simulations. The figure shows the compression process of the three-layer new biaxial negative stiffness honeycomb unit structure.

[0057] In the present invention, a three-layer conventional hexagonal honeycomb unit structure with the same thickness t as the three-layer novel biaxial negative stiffness honeycomb unit structure is manufactured, and an experiment is conducted on the three-layer conventional hexagonal honeycomb structure with the same compression amount, such as Figure 7 As shown, the comparison is carried out through experiments, such as Figure 8 As shown, it is verified that the three-layer new biaxial negative stiffness honeycomb unit structure has better mechanical properties and repeatability.

[0058] The mechanical properties and energy absorption effect of the negative stiffness energy absorption structure in the present invention are mainly affected by the following parameters: the thickness t, amplitude h, and center angle θ of the negative stiffness beam peak structure. Figure 1 The local schematic diagram of a single unit is shown in Figure 3 shown.

[0059] In the present invention, unless otherwise specified, the materials used for simulation are all commercially available products well known to those skilled in the art.

[0060] Example 2

[0061] A new biaxial negative stiffness honeycomb unit structure is prepared using TPU (polyurethane) material.

[0062] TPU material parameters: Young's modulus: 40MPa, Poisson's ratio: 0.39, density: 1230kg / m3;

[0063] Step 1: In the SolidWorks modeling software, a model of the improved new biaxial negative stiffness honeycomb unit structure is established, wherein the geometric dimensions of the unit structure are: the central angle θ corresponding to the new biaxial negative stiffness honeycomb unit structure is 20°, the cosine period length L1 of the lower half of the outer layer of the new biaxial negative stiffness honeycomb unit structure is 50.8 mm, the cosine amplitude is h=5.08 mm, the beam thickness is t=1.27 mm, and the column thickness is 2.54 mm. To ensure that the Q value of the upper and lower beams is the same, the upper and lower cosine beams maintain the amplitude of 5.08 mm when the beam thickness is consistent. At this time, the period length of the upper half of the beam is determined according to the beam position, and the period length L2=45.43 mm. After determining the geometric dimensions, a stretching thickness of 12.7 mm is performed on it;

[0064] Step 2: Save the established geometric model as stp format, import the generated geometric model into the 2021 version of ABAQUS software, and establish a discrete rigid shell plate as a simulated rigid plate.

[0065] Step 3: Input the material parameters, create the solid cross section, assign it to the new biaxial negative stiffness honeycomb unit structure, and assemble the unit structure and rigid ground;

[0066] Step 4: Using the dynamic implicit analysis method with quasi-static effect, the time length is set to 1s after the initial analysis step to simulate the compression process of the ground compression negative stiffness unit structure;

[0067] Step 5: Create an interaction property as contact, set tangential behavior and normal behavior in the contact property, set the tangential behavior friction formula to "penalty", set the friction coefficient to 0.2, set two interaction types, interaction one is general contact to prevent the models from penetrating each other, interaction two is surface-to-surface contact, the main surface is the ground, and the secondary surface is the outer surface of the bottom of the structure. At the same time, a coupling constraint is set on the inner arc surface of the structure, and the constraint control point is at the center of the cylinder, so as to facilitate the subsequent control of the inner surface movement; a rigid body constraint is set on the ground to better simulate the properties of the plate;

[0068] Step 6: Set the center point of the cylinder coupled with the new biaxial negative stiffness peak-to-dimple unit structure to a completely fixed state. In the first analysis step, apply a displacement load of 19.06 mm to the center of the cylinder on the rigid ground.

[0069] Step 7: Mesh the components. For the unit model, hexahedron-based units are used. The neutral axis algorithm is used for meshing. For the ground model, quadrilateral-based units are used. The advanced algorithm is used for meshing. The unit size of the unit model is 0.5. The rigid ground grid is coarsened to balance the solution accuracy and solution efficiency. The grid size is 2.

[0070] Step 8: Create a job and submit it for analysis to obtain the force-displacement curve of the unit structure;

[0071] Step 9: On the basis of the single-layer structure, the number of layers of the new biaxial negative stiffness honeycomb unit structure is accumulated to obtain the two-layer and three-layer negative stiffness honeycomb unit structures as follows: Figure 4 As shown, the finite element analysis of steps 1 to 8 is performed on the two-layer and three-layer negative stiffness honeycomb unit structures respectively, and the force-displacement curve of the three-layer negative stiffness unit structure is obtained as shown in Figure 7 As shown;

[0072] It can be observed that as the compression progresses, the three-layer negative stiffness unit structure gradually undergoes buckling deformation. When the compression exceeds a certain value, the structure will experience two situations in which the force and displacement increments are opposite. This is the negative stiffness effect.

[0073] pass Figure 7 From the force-displacement curve of the three-layer negative stiffness unit structure, it can be seen that the three-layer structure has negative stiffness properties and will show mutation characteristics under compression loads. Further analysis shows that with the addition of the number of layers, the force threshold of the negative stiffness spoke is also increasing, that is, the structure has better load-bearing compression performance. The maximum force threshold of the single-layer negative stiffness unit structure is 1.771N, the maximum force threshold of the double-layer negative stiffness unit is 13.08N, and the maximum force threshold of the three-layer negative stiffness structure is 19.81N. In this load-bearing compression simulation, the higher the critical value of the load force required to express the negative stiffness behavior, that is, the higher the negative stiffness behavior force threshold, the better the load-bearing compression performance of the structure, and the three-layer negative stiffness unit structure shows better advantages in load-bearing compression performance.

[0074] Example 3

[0075] After obtaining the negative stiffness beam peak-nest unit structure with the best load-bearing compression performance, the Aurora Elvo 3D machine was used in conjunction with the 3D printer software JGcreat to print out three layers of negative stiffness peak-nest unit structures and three layers of traditional hexagonal honeycomb unit structures with the same thickness t, and the electrical universal material testing machine 7500LA produced by Dongguan Zhiqu Precision Instrument Co., Ltd. was used to conduct quasi-static compression experiments at a compression speed of 6mm / min.

[0076] The dimensions of the three-layer negative stiffness beam peak cell structure of this embodiment are the same as those of embodiment 1. Under the premise of satisfying the same thickness t, the printing thickness of the traditional hexagonal honeycomb is 1.27 mm. The same compression amount of 26 mm is applied to the three-layer negative stiffness beam peak cell structure and the three-layer traditional hexagonal honeycomb cell structure. The compression process of the three-layer negative stiffness peak cell structure is as follows: Figure 6 As shown in Figure 2, the compression process of the three-layer traditional hexagonal honeycomb unit structure is as follows: Figure 8 As shown, the compression force-displacement curve is derived as Figure 8 As shown;

[0077] By comparison Figure 8 From the curve diagram of the three-layer negative stiffness peak cell structure and the three-layer traditional hexagonal honeycomb cell structure, it can be seen that with the increase of displacement, the force of the three-layer honeycomb structure gradually increases, and its maximum value is 8.82N. The load-bearing compression performance of the three-layer negative stiffness honeycomb cell structure is much higher than that of the three-layer traditional hexagonal honeycomb structure. After unloading, the three-layer traditional hexagonal honeycomb structure can also be restored to its initial state, but there is a warping phenomenon at its corners. At the same time, after carrying out 10 consecutive loading and unloading experiments on the three-layer negative stiffness peak cell structure and fitting its force-displacement curve to the same coordinate system, as shown in FIG. Figure 8 As shown, it can be seen that the force-displacement curves of the three-layer negative stiffness honeycomb unit structure are basically coincident, and the three-layer negative stiffness peak-cell unit structure can be well restored to the initial state, that is, compared with the three-layer traditional hexagonal honeycomb structure, the three-layer negative stiffness peak-cell structure has better repeatability.

[0078] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A novel three-dimensional cylindrical negative stiffness energy absorbing structure, comprising an energy absorbing structure body, characterized in that: The energy absorption structure body is composed of inner and outer cylindrical surfaces and an internal periodic structure. The internal periodic structure is provided with a periodically distributed novel biaxial negative stiffness honeycomb unit structure (1). Each of the novel biaxial negative stiffness honeycomb unit structures (1) is provided with two upper and lower bending beam structures.

2. A novel three-dimensional cylindrical negative stiffness energy absorption structure according to claim 1, characterized in that: The interior of the energy absorption structure body is composed of three layers of negative stiffness hyperbolic beam honeycomb unit structures, and each layer of the negative stiffness hyperbolic beam honeycomb unit structure is composed of 18 new biaxial negative stiffness honeycomb unit structures (1).

3. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The parameterized model of the curved beam is: F=fl 3 / (Elh) Δ=d / h Q=h / t In the formula, is the average distance from any point on the bending beam to the horizontal line connecting the two ends of the beam, h is the amplitude of the bending beam, x is the position on the horizontal line, l is the horizontal length of the bending beam, f is the external force, E is the elastic modulus of the buckling beam material, I is the moment of inertia of the beam, t is the thickness of the beam, d is the lateral displacement of the bending beam, and the geometric parameter Q determines the direction of the relative stress-relative displacement curve. Changing the Q value adjusts the stiffness of the bending beam.

4. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The cosine period length of the hyperbolic beam in the lower part of the new biaxial negative stiffness honeycomb unit structure located in the outermost layer is 50.8mm, the cosine amplitude is 5.08mm, the beam thickness is 1.27mm, the column thickness is 2.54mm, and the beam period length of the upper part of the new biaxial negative stiffness honeycomb unit structure located in the outermost layer is 45.43mm.

5. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The cosine period length of the upper semi-hyperbolic beam of the novel biaxial negative stiffness honeycomb unit structure located in the middle position is 38.92 mm, the cosine amplitude is 5.08 mm, the beam thickness is 1.27 mm, and the column thickness is 2.54 mm.

6. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The cosine period length of the upper part of the hyperbolic beam of the new biaxial negative stiffness honeycomb unit structure located in the innermost layer is 32.31 mm, the beam thickness is set to 1.27 mm, and the cosine amplitude is 5.08 mm.

7. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The new biaxial negative stiffness honeycomb unit structure located in the middle position has a thickness of 62.42 mm on the radius of the new cylindrical negative stiffness energy absorbing structure, and the new biaxial negative stiffness honeycomb unit structure located in the innermost layer has a thickness of 81.43 mm in the radius direction of the new three-dimensional cylindrical negative stiffness energy absorbing structure.

8. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The diameter of the novel three-dimensional cylindrical negative stiffness energy absorbing structure is 338.29 mm.

9. The novel three-dimensional cylindrical negative stiffness energy absorbing structure according to claim 1 is characterized in that: The thickness of the three-layer hyperbolic beam honeycomb unit structure in the radius direction of the new three-dimensional cylindrical negative stiffness energy absorbing structure is 81.43 mm, and the inner diameter of the new three-dimensional cylindrical negative stiffness energy absorbing structure is 175.43 mm.

10. A design method for a novel three-dimensional cylindrical negative stiffness energy absorbing structure, used to realize a novel three-dimensional cylindrical negative stiffness energy absorbing structure as claimed in any one of claims 1 to 9, characterized in that: include: S1. The new biaxial negative stiffness honeycomb unit structure is made of polyurethane material and is integrally processed by 3D printing technology; S2. When verifying the mechanical properties of the new biaxial negative stiffness honeycomb unit structure, the load-bearing compression performance is verified by the finite element software ABAQUS. The specific process is as follows: A unit structure model was created in SolidWorks software, imported into ABAQUS, a rigid plate was created to simulate the ground, material parameters were set, and sections were created for it. Both the unit structure and the ground were solid sections. The dynamic implicit analysis step is selected, which has a quasi-static effect and is used to simulate the quasi-static compression process. The surface-to-surface contact is adopted between the lower surface of the unit structure and the upper surface of the rigid ground. The friction coefficient is determined according to the actual situation. The penalty function calculation method is adopted. The general contact is set for the overall structure in the initial analysis step to limit the geometric penetration between the models. The upper surface of the unit structure is coupled to the center of the cylinder, and the rotational and translational degrees of freedom of the center are restricted to 0, which is in a completely fixed state. The rigid ground is set as a rigid body, and an upward displacement is applied to it. The unit structure uses the element C3D20R to mesh the structure, defines the approximate global size as 0.5, and performs nonlinear effect analysis on it. The rigid ground uses the R3D4 discrete rigid element; After determining the compression performance of the single-layer new biaxial negative stiffness honeycomb unit structure, the number of layers is accumulated on the basis of the single-layer structure. The simulation process of the two-layer and three-layer biaxial negative stiffness honeycomb unit structures is the same as above.

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